i would get a couple of cans of break cleaner. degreaser might help, but that buddy knife and break cleaner are going to expedite the process faster

the puddy knife and maybe a couple of smaller sized punches to get in the little knooks and crannies is a good idea. Mine was caked on about 3/16" thick. I scraped about half of it off and realized i was going to have to get my  into it. 

good luck. if you still have axle grease inside, break cleaner isn't going to just spray it out, so don't waste your time. take a shop rag and get in there and scrape it out, then break clean, then scrape it out again. I'd say without soaking the parts, it took me a good hour and a half from start to finish to get them both clean. good luck